Citrus Systemic Pathogen Research

The main research emphasis in this research program is in the detection and identification of the causal agents of systemic diseases of citrus. Current areas of research are on citrus tristeza, citrus blight, citrus variegated chlorosis, leprosis and huanglongbing (citrus greening) diseases. The detection of the causal agents and their specific strains are important in the control of these systemic diseases of citrus. We use microscopy combined with other detection methods to specifically visualize systemic pathogens in citrus tissues. Many systemic diseases of citrus are insect vectored and therefore much of our current work concerns the interaction of pathogen, vector and plant. Much of our vector work is on exotic citrus diseases such as stem pitting tristeza, citrus variegated chlorosis and huanglongbing and must be conducted in quarantine facilities outside citrus production areas. These studies include the separation and identification of the tristeza virus complex using the brown citrus aphid, the vectoring of the citrus variegated chlorosis bacterium with sharpshooter vectors from Florida and California and the vectoring of the huanglongbing bacterium, Liberobacter asiaticum, with the citrus psyllid, Diaphorina citri from Florida. Any questions concerning our research program are welcomed.